Palladium-Catalyzed Arylation of 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) with Halogen-Substituted Phenols

Abstract

Phenol functionalized 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivatives are synthesized via palladium-catalyzed arylation of DOPO with halogen-substituted phenols. 2-,3-, and 4-Substituted halogen phenols are successfully applied to the cross-coupling reactions. This method is mild, convenient, and leads to high yields (65–95%).

Keywords:

• Arylation
• catalysis
• cross-coupling
• DOPO
• palladium

We thank Shenyang BMD Chemical Co., Ltd. (China) for funding this project.

Notes

^a The reactions were carried out using DOPO (1 mmol), 4-iodophenol (1 mmol), and base (2 mmol), in dioxane (3 mL) at 100°C under nitrogen atmosphere.

^b Isolated yield.

^c i-Pr₂NEt: N,N-diisopropylethylamine; Cy₂NMe: N,N-dicyclohexylmethylamine.

^d CH₃CN (3 mL) was used as the solvent and the reaction was carried out at reflux temperature.

^a The reactions were carried out using DOPO (1 mmol), halogen-substituted phenol (1 mmol), and NaOAc (2 mmol), in dioxane (3 mL) at 100°C under nitrogen atmosphere.

^b Isolated yield.

^c Method A: Pd(OAc)₂ (5% mol), Ph₃P (10% mol) were used as catalysts. Method B: Pd(Ph₃P)₄ was used as a catalyst.